Elastic-support system for vehicles



April 12, 1921 '1,624,643

F. L. o. wADswoRTH ELASTIC SUPPORT SYSTEM FOR VEHICLES Filed Dec. 16, `1922 4 sheets-sheet 1 4 Sheegts-Sheet 2 F. L. o. wADswoRTH Filed Ds. 16, 1922 ELASTIQ SUPPORT SYSTEM FOR VEHICLES April' l2, 1927.'

April 12, 1927. 1,624,643

F. L. O. WADSWORTH ELASTIC SUPPORT SYSTEM Fon VEHICLES vFiled Deo. 16, 1922 4 Sheets-Sheet 3 maiz.

April l2, 1927.- 1,624,643

F. L. O. WADSWORTH ELASTIC SUPPORT SYSTEM FOR VEHICLES Filed Dec. 16, 1922 4 sheets-sheet 4 FIGJB.

uukY/ZZ/ I port elements are operatively connected, andl act, inseries when the system is subjected to @A furtherobjectjof in parallel with this same spring in)l resist- Patented Apr. 12, 19277.

frruNiTED ,STATES heie FRANK L. O.WADSWORT, OF PITTSBURGH, PENNSYLVANA.-

ELAsTic-snrronr sYsTEMroavnHrcLns.. i

` Apparaat-roamed December igieaaj seiiai No. 607,308..

i Myinvention relates, inY general, to'that type of elastic support systems Vthat comprises a plurality of springs which are con-V joined in such manner as to resist any dis-` placement from `normal load `position by;

- joint and progressivelyv increased ileXures of all of the said springs; andoneof the primary. purposesof the present improv'ef mentssto provide a systemV of this character in which two or'more of the elastic supcompression stresses, and are dierently coupled to actin parallel when anexpansion or rebound shock is imposed thereon. O r statedinanother way, onejof the important features and objects of this invention is the provision of operative means' whereby ai compression, orkinetic load, shock may b e transmitted through, andl absorbed by, a plurality of series-connected springs, and

wherebyl an expansion or rebound stressmay loe-communicated to, and restrained vby the f same springs when coupledin parallel,` or multiple relationship.

is' the provision of a combination of primary and secondary springs wh-ich are so connected with leach otherv as topeXert an interbalanced series 'action in "restraining andv f abat-ing the effects .of a temporary increase which is operatively connected therewith lin such manner Vas to act directlyin series with thev main j spring in opposing the approach of--the body and faxle members, and vto'act ing and checking the abnormal separation of theelastically supported parts. i f' Another specific object ofthe present invention is to provide an improved formY of supplemental spring suspension kelement whichpresents an elastic resistance to any movement of the `spring supported parts'y away. from the position of statief equilib Vrium-i. e., to veither compression or rebound displacements-tand vwhich vis damped or rethe present inventionv rENrortica strained in itsfsubsequent recoil lorwreturn" movements to saidrnormal position. j v y Other special features and advantages of the lherein described invention will jbe .made

apparent, to thoseskilled in lthisV art, by the accompanying .explanationvyof certain, illus#y trative embodiments thereoffthat are shown inthe drawings, inv which: f

-Fig lis a sectional elevation, on lthe longitudinal central plane, of oneexemplill-y cation of my improved Vsuspension system.

as appliedfto the rear 'v axle support .of va motorvehicle: Fig.,` 2fis=a .side view-'-pa rtially in section on the sameplane as Fig.

l-'of Vthis same construction "with the'parts thereof in tli-e'positionof rebound or eX-E pansion; 3 is a sectionalplan .viewon theplaiiew of Fig. 1;,Fig.g4t is an eleval tion-in .partial sectionf Yon its central plane-of a second embodiment off my invention as it-may be used in conjunction with the frontaxle mounting of any auto mobile; Fig.'5v is an enlarged sectional view` offthe supplemental spring member ofthis second organizationwith the parts. thereof in the position of eXtreme compression;Fig. ,f

.6 isa similar vieWfo'f this same member and.

showsthe parts in the position which they assume under a rebound or expansion shock;V F ig.V 7 Vis a sectional plan view on theV bentV plane 7-C of Fig.w 5; Fig. 8 is a partially sectioned elevation# of one ofA myl improved forms ofv air lspring 'constructionl that may besubstituted for either'fone of, the corre? Figs. 1 and 2,- orFigsf-if and 6; Fig 9is another view of `this. third form of supple# mental 4spring [construction with the y,Parts expanded lunder 'i the",` action .lof rebound stress; Fig. 10 isa cross-section, on the plane 10-1'0 of Fig.8; yand Fig. 11 isa detail 'secf A' tional viewfon a` still larger scale-of `a portion of the .mechanism shown in Fig. 8.

l, `On the third and ,rfffourth sheets of my drawings: Fig. 12 isa side elevation ofa third complete embodiment of the present ,1i

improvements; Fig. 13 is an enlarged sec.- tional elevation of lthe. supplemental Vspring member of that combination, Fig. 14C is another 4vieW--on .a still larger scale-of a portion of the construction .shown in Fig. v

13, with the parts thereof in a` partially eX- pandedwposition; Figs-15 andV 16 are'side views cfa fourth .exempliiication of my in- '110- vention. and respectively illustratezthe main Y suspension elements'in the positionsofnoi;

90 Y spondingmembers thatnarey illustrated iin" mal load (or static equilibrium), and of eX- treme rebound (full lines) and extreme compression (dotted lines); Fig. 17 is a partially sectioned elevation of the supplemental spring elements of the last mentioned combination (with the parts in the normal load position of Fig. and Fig. 18 is a vertical section of these elenientsV in kthe position shown in Fig. 16.

structural combinations.

In the `first exemplilication of my improvements (Figs. 1, 2 and 3) the main leaf spring 1 isv pinned at its inner end to the body of the vehicle and is bolted at its center to the rear axle block, in the usual manner; but the outer end of this primary suspension member is detached from the rear horn of the chassis frame and is flexibly connected-as by the shackle links 4, l--to the adjacent Vportion of a lever support 5 that ispivotally mounted, at 6, on the axle block bracket 8. The outer extremity of the lever 5 is pinned, or otherwise flexibly coupled, to the lower end of a plunger 9 which slides vertically in a casing member 11 that is rigidly attached to the body horn 2 by the bolts 12, 12 etc.; and the inner end of the said lever is, also flexibly. coupled to the body sill by means of the one way strap connection 13. The vertically reciprocable plunger 9 is provided, near its center, with a shoulder le which isadapted to engagea central liange onI an inner sleeve 15.; and the latter is, in turn, connected to the upper cap 11 of the casing by means of the one way follower bolt 16. The upper part of the plunger 9 is flared, outwardly to engage the inner surface of the casing 11, and is provided with a second shoulder 17 that engages with a flanged collar 18 that is limited in its upward Inovement by the lower end of the casing cap 11". A volute coil spring 2O is inserted, and held at a predetermined initial tension, between the central flange of the inner sleeve 15Y and the cap 11'; and a second spring, 21, of similar form is interposed, and likewise maintained at a normal preadjusted compression, between the collar 18 and the botjust above the contiguous extremity of the inner sleeve 15. The lower end of the casing is likewise provided with a vent opening that is covered by the downwardly opening valve 26, and the side of the casing is perforated by a port 27 that is positioned just below the edge of the outer sleeve 18 `Awhen the latter is in its raised position.

The various parts of this suspension Vorganization are so proportioned and assem-k bled that when the system is subjected to the ordinary or normal load stress the loadcomponent on the body horn 2, and the initial tension on the supplemental spring 20, will hold the central flange ofthe sleeve 15 in light pressure engagement with the head of the suspension bolt 16-as shown in Fig. l-against the reverse upward thrust of the outer flexed end of the main spring 1 and itsV conjoined lever and plunger elements 5 9; and in this position of the parts the one wayconnection 13 is also preferably maintained under a light tension. In order to provide a certain range of adjustmentunder varying normal loads-the pivot -connection 6 is made up of a central bolt,V that passes through the ears of the forked axle bracket 8, and an eccentric bushing 6" which forms the pivotal bearing for the lever 5, and which vcan be clamped in any desired angular position, between the said'ears, by

the nuts on the ends of the saidY bolt. The pivot connections at the ends of the strap 13 are constructed in a similar manner and thelower one of these connections can also be shifted longitudinally with respect to the lever 5 by providing the inner forked end ofV the latter with a series of holes or an equivalent slot 28. Y

l/Vhen the normally loaded system is subjected to kinetic increases in load-such as will be imposed by the compressive shocks due to the passage of the wheels over irregula-rities i-n the road' surface, etcthe body and axle parts will be forced towardeach other, and the initial or normal iiexure of the series connected springs 1 and 2()` Vwill be concurrently and progressively increased to balance and sustain this augmented compression stress.V This action will straighten Vout the bowed leaf spring 1 and will correspondingly rockthe lever 5 in a counterclockwise direction on its pivot support 6- thereby relieving the tension in the strap connection 13-and the bodily approach of the spring supported chassis members will move the plunger 9 and the inner sleeve 15 upward with respect to the casing parts ll-llk-ethereby compressing the upper supplemental spring 20-without cha-ngingrthe position and initial tension of the sleeve 18 and the lower auxiliary spring 21. The upward movement ofthe sleeve 15 on thebolt 16 closes the port 24, and the air above the rising plunger 9 is expelled, in part, through lili fthe valve 22. order ytoreducethe volume `of'the free space inthe top of the 'casing 11'-`and thus increase the; volumetric contraction and vexpansion ofA this Aspace-the flanged cup shaped" portion of the plunger 9 mayibefilled with a; heavy viscous'oil or grease'le. g., to the level Ln) which will also servetokeep all of the reciprocating parts `clontinu'o'usly lubricated.' lWhen the compres- 'sion" movement has' been arrested-by the progressively increased flexural strain in the 'series-connected elastic 'suspension unitsand the. parts begin ,to move backward toward'normal loadpositiom the valve 22 will close; and therecoil'- ofthe compressed supplemental' springv 2Ofwilly be` retarded or jpnieumatically dampedfby the formation of" afpartial j vacuum above the downwardly moving 'plunger- 9. As' this return move` "ment continues the restraint imposed on the recoilorexpansion ofthe spring 20,V and Y its Yco-moving parts, willbe constantly inf'creased both by the progressive reduction in pressure in the`top of the casing 11 Vand by Vthe concurrent reduction inthe tension of the expanding'coil; andl the compressed members may thusbe prevented, in many in-` stances, from recoiling or rebounding beyond A' the :normal load position on this Vreturn movement. When the conditions of static .equilibrium have thus been restored the port 24 vwill be againopenedand the upper `end Y ofthe casing chamber will be'reiilled with air at atmosphere pressure. f

When the compression movement has been so violent, or of suchgreatA amplitude, as to make it impossible to check a vreboundorl overthrow of the partsbe'yond normal load' vpos ition,- or when the suspension system is subjected to an expansion stress by the dropnping vof the wheels'into deep cavitiesin the roadsurface, ete-the Oneway connection 13 is brought intoplay to positively rock the lever 5` on its axle support 6; and thel resulting accelerated v moveinent of the outer extremity of this rockingl member produces a'nincreased positiveflexure of the mainj s rinor 1` and coincidentiy im oses'an inb n r movement ofthe engaged plunger and sleeveV elements 9-17f18ge-the upper supplemen--` tal spring 2O being now held against 'fur-. ther expansion by the follower bolt 16.* The main spring 1 and the auxiliary spring 21 creasedV compression on the auxiliary rebound spring 21by reason ofthe downward are thus increasingly .flexed iny parallel relation; Y and Vthe ,combined elastic resistance which they together 'offer to the abnormaly or supernormal separation of the body and axle= parts very .quickly checks any, rebound .or expansion movements, regardless of whetherV they maybe retarded or accelerated bygravity action.

During the downward movement ofthe interengaged plunger and sleeve elements 9 18 the port 27 lwill be lirst'closed, and l' the remaining yair in the lower .end of the f'casing chamber will be partially expelled through the outwardly opening vvalve 26.

Therecoil ory returny movement of the com'- pressed rebound check spring 21 will then be retarded or pneumatically damped bythe closure of the valve 26 and the progressive dropy in pressure below the upwardly moving piston parts 9-18. -When thesev parts have been restored toV their normal' static loadl positions the port 27 will be again opened, and the lower end of thecasing chamber will berelled `with air atatmosphere pressure. Thesecond exemplification of'my present invention (Figs. 4 to 7) .is designed foruse jinl conjunction with a front axle support. "In such an orgaiiizationthe center Y ofthek "main side leaf spring 1" is'boltedrigidly to the under-slung' axle member A and the inner extremity thereof is usually connected :to

the bodysill by a swinging shackle link connection (not shown here). The frontv or outer endy of this primary suspension ele-` ment'isjpinned directly to the forward part of a forked, or twinarm, lever support 5a;

ible loop 13EL of leatheror other suitable'v fabric, that is rivetedfor -otherwise'secured to the lever, 'andis loosely engaged with the 'lower leaf of themain spring.r 'Theplungei' v18EL slides'in the elongated central hub o'fan annular cup shaped' piston 15a that yis. fittedM closely in the casing support 1l, andftlie latteris rigidly attaclied to tliefrontliorn 2 bythe bolts 12a.V A supplemental-suspensionspring 20V is `interposed between.L the `head ofthe plunger 1.8a and/the lower closed end ofthe 'piston`15;' land the downward Y movement of this piston is limited by'an'- in- '.wardly turned iange 16a on the casing support 11a. The cap of the casing is providedy .1

with a vent which is closed by an outwardly opening ball `valve 22a; andthe central ico liol

plunger is provided with a'- duct 23a' which y 'the casing chamberA at a point just vabove'fthe central hub of thepiston 15a, when the 'two reciprocatingmembers, 15a and 18, are in their normal load positions (see Fig.

VThe A`mode of operation of this lastdescribed-construction is as follows: Under the conditions of static equilibrium theparts are in the full line positions shown in Fig. 4:, in

plemental spring 20?- is suflicient to carry the' normal' component of 'the load stress on* leads from the slot in the 'lower'endfof this- 1 member to a lateral port 24a, that opens into which `theyinitial tension of the conlinedsupc the body horn 2 and hold the piston and plunger elements, 15a and 18a, in light pressure-engagement with the opposite ends of the casing support 11a; and in which the strap 131L is Aalso held in light tensioned engagementwith the main spring and lever elements l and a;--this last specied condition being readily established, after the suspension system is completely assembled,

by Vvarying the length of the adjustable turn buckle link 6, When, under such conditions, the system is subjected to a kinetic in- 'crease of load, (e. g., a compressive shock), kthe axle and body parts will approach each other; the main spring l will be increasingly flexed and straightened out; the lever 5a will fbe 4moved upward with the end of the main spring; and the engaged collar and piston members, Slawill 'be correspondingly lifted toward the casing supported head of the inner plunger 18a; thereby compressing the supplemental spring 20EL in series with the main spring l. The upward movement or' the pist-on hub on the plunger 18at closes the port 24a, and the air in the casing chamber is then expelled through the lvalvevZQa as the upward movement continues. When the compressive shock has been absorbed'by the progressively increased elastic resistance of the two series-connected springs l and 20a, the parts will be returned to normal load position N-fn, (Fig. 4) by the recoil of .l `the said springs; and this return and recoil movement will be retarded and damped by separated bzeyond normal load position--V e. g., by a rebound or overthrow ofthe elastic suspension elements after they have been subjected to unusually severe compression strains, or by an expansion stress-the strap lawill positively Vrock the lever 5a in a clockwise direction on its body support Ga, and the magnilied movement of the outer Yend of this Vlever-will produce an increased Jflexure in the main spring 1;-as shown by the dotted line R-r of Fig. 4.

yment will be simultaneously communicated This moveto the inner plunger' 15in-through the engagement of the collar 9LL with thenut on the lower rend ot said plunger-and the spring 20il will be thus compressed, in parallel with the main springl l, by the relative approach of the parts 18a-malas shown in Fig. 6). The initial downward motion of the plunger 9a, with respect to the central hub of the casing supported pist-on 15a. will .again close the port 24a; and the continued motion ot' ythe said member will result in a reduction of pressure in the expanding space above the the operation ofthe irst described organi-P Zation.

In order to reduce the volume. of freeY air 1n the top oi the casing chamber-and thus accentuate the expansion or suction effect produced by the downward movements of either the piston member l5a or the plunger member 18a-the cup shaped piston` may be {illed with a thick oil or a light grease t0 the level L (Figs. 5 and 6) and the slight splashing of this material over the edges of the receptacle will serve to keep all of the mutually reciprocating parts in well lubricated condition.

Figs. 8 to l1 illustrate an improved form of supplemental air spring construction that may be used in conjunction with either one of the complete suspension systems heretoii'ore described. ln this alternate exemplification of this feature of my improvements, thev outer end of the lever 5EL (or 5) is slightly modified in form, and is connected to the lower end of a cup shaped plunger 9b, by means of the shackle link 30. rlhe lower head of' the piston 9" is provided with two lugs Simili which carry Vset screws 32-32 that are adapted to engage the edges of the link 30. Then the supplemental spring is used in conjunction with a front'axle support (as'shown in Fig. 4) the link 30 is clamped rigidly in place between the screws 552-32, and the end of the lever 5a is thus held in fixed axial relationship to thereciprocating plunger 9b. In this case the outer eye end of the main spring l is pinned directly to an adjacent portion of the lever, by the cross pintle bolt 4a; and the interconnected parts l and 5a thus act as -a radius rod to maintain the liront axle in a predetermined position with 'respect to jthe plunger support 9b. lIf it is desired to use y the supplemental spring as a part of a rear axle suspension systemsuch as is shown in Fig. l-the screws 32-32 may be withdrawn so as to permit ofv a relative longitudinalv movement of -the main spring and lever'elements (l and 5) with respect to the axis ot reciprocati-on of the plunger.

The plunger 9 slides vertically in a casing 1lb which lis rigidly attached to the body horn 2 by means of thebracket 33 and the bolts and screws 12'9-34, etc. The upper end ot this casing is closed by afcap 11b" to which is attached an inner casing sleeve 35 that is also closely engaged bythe upper end ofthe plunger 9": The lower extremity of the sleeve 35 is enlarged `to receive an annular flanged head 36; Vand the inwardly turned shoulder Von this head vengages with an inner cup yshapedplunger, 37, that is seated on a central boss at'the. lower end of the outer plunger'rQb :This Vboss carries afollower bolt 181 that extends up through a metallic packinggland38 inthe member 37 and is lprovided atits upper end with an adjustable'headv 39. A coil compression spring 21bfis confined, at a pre' determined initial tension, between the head 39 and the rim of the inner plungerv the head 36. VThe lower ring 43 isprOVided i "on one side with agroove 45 that extends from'its upper edge to avpoint near :its

center,"and witha port 46 that connects the `si'de-fwith a recess vor pocketwhich is in' lregistry with the upper end-of the groove .713,5 and'which contains an inwardly openingball lower end of this groove Y.with the "space `be'- tween the rings 43-44 and the Ywash'er'42. The upper ring 41 is .also provided,Y on one valvej471; Y and itl has a port 48 thatleads from the seat of this valve tothe outer recessed face of the ring. 'The' lower portion.of the..V

head 35`is valso providedwith a duct 49-that .is inregistry withthe groove 45 andthe port 46 of the lower ringv 43. lThe upperV end' of the plunger` 9b is provided with; a leather'piston washer 50* that is securely wired'to the upper grooved or corrugated edge ofthe said plunger; vand the assembled casing members 11b-33 are provided with an inwardly opening valve 51, and a port 52 thatleads to the lower end of the'annular` chamber 53 inwhichthe end of the outer plunger19", and itsattaehed piston washer 50. reciprocate.

' vIn the use of'this supplemental spring structure the reservoir or chamber between the plunger 9b andthe casing sleevel 35 areV partially filled withl oil-fe. g., to the nor-v mal Vlevel L ofvFig. 8-and the compressed air is theny introduced` through a "suitable valve 29 in the casing cap,luntil the pressure of thevsaidairrinthe upper part of this chamber (20), is sufficient tocarry the norvmal load component'on the lbody-horn 2y and maintain the inner plunger 37 in` light pres# vsure engagement with the lflanged head 36.

vllVl'len the system is sub'ecte'dl to' a. kinetic in# creasein load theouter'plunger 9b' is lifted relativelyrto the 'casing` 11",V (carrying with .it the members 37--38-18*-39--21b and 21'b) and an'opening is formed between the parts 36-'37 (as shownin Fig. l11);through which `the oil in the lower part of the air springv canpass freely to the upper compart- Y ment thereof. In this ,phase of the operation the oilbelowy the head 36 is subjected to the `full pressure ofthe confined fluid in the upper chamber A201%; and this pressure is transmitted, through the communicatingV ducts 49-,46, to the inner Vface-of the packing washer 42, and serves toforce thatmem v ber into close sealing Vengagement withthe inner'wall of the vplunger 11b. lThe pressure 1n the duct 45 also closes the .ball valve 47 and preventsV any escape of'oil through the lport 48. vThe continued approach movement of theplun'ger and casing members, Sib-e111?,

`progresslvelyidecreases the Vvolume,'and increases the pressure',fof the confined air, and

sov

thus produces a constantlyl increasing Vsupplemental spring resistance that acts in` series .Y

with the' concurrently'flexed `main spring 1 in absorbing and checking the compressive shock. The upward movement `of the plunger 9b, relatively tothe double walled 'casing 11b-35, will compressthe air that is con-V fined in the annular chamber above the pisto n 50; and thissame movement will also slightly expand the air that is trappedfbe- Vtween the upper head of the outerrplunger ,l

andthe washer 40 on-,the inner' casing sleevez u Both of these actions will ,supplementv the compression of the'fiuid in the main air ,spring chamber in'resisting the relative lap-v l -proach of the,v body and axle parts. The an-y nular space 53 below the upwardly moving p1ston50 is kept. filled'with air at atmosphericpressure by the openingof the check valve k51; and when the .return movement springis moderatedby the closing of this ber. Y

units is so violentas to carry the partslbeyond normal load position (or vrwhen the system is otherwisesubjected to expansion stresses) the separation'of the'plunger and casing members 9b-11b.+351willmove the head 39 toward the engaged parts 364-37-,-

38,. and will thereby compress the .auxiliary coil springsv 213,211. The reengagementof f -the head Cand flanged cup elements 364437 cuts ofi' communication betweenthebottom part of the air spring chamber, and the upper. part thereof` (20",) and. the. continued ytive to they casing lowers the level of the oil in this'lowercompartment (e. g., to thelevel lLf .of Fig. .9)Y and creates a partial yvacuum (under nthe head 36,- which-supplements the begins, the l recoil of the compressed air -valve and the subsequent compressionjof the .air that is thusytra'pped inthis ou'tercham- 11e When theA compression is f very vsevere and v the following recoil of the compressedspring 12,5 j vdownward movement of the plunger relaf las action of the vauxiliary springs 2lb-21" in quicklyfabating and arresting the rebound vor supernormal expansion of the suspension tween the ring il and the washer 40, will now i'l-ow back into the expanding space below the head 36.

The rebound or expansion movement of the relatively reciprocable parts 9b and 11b (beyond norinalV load position) will further compress the air that was initially compressed in the space 53 (by the return oit the members from the position of compression); and will also result in somev compression of the air in the annular .space above the packingl washer 40; and these effects willfurther .supplement the cooperativeY actions oit the springs 2lb and 2lb, and of the vacuum check7 above described. All of these pro gressively increased elastic resistances to rebound actin parallel, or, in multiple, with the simultaneously increased flexural strain that is imposed on thermain spring by the forced angular movement of the lever support 5a (or 5), when the aboveI described supplemental spring construction is used as a vpart of the-complete combinations shown in Figs. l to 7 Y Y The air which is compressed in the chainber 53 will be pre-vented fromv passing into the'chamber aboverthe outer plunger 9band thence into the space between that plunger and the parts -aO-lll, etc-by the close engagement between the plunger and washer members 9b50 and the walls of the Vcasing sleeves 11b-35; and -the pumping of outside air into the .lower compartment of the air spring (duringiebound movements) in thus avoided. But a part of the air thus compressed will escape through the bearing between the plunger 9b and the lower part of the casing 1lb; and this escapewhich can be regulated in lamount by the bearingl clearance between these parts-assists in expelling or excluding dust and dirt'from this sliding joint. The drop 'in pressure that results 'from this escape will diminish the aggregate ojt' vthe elastic forces that tend to restoi'e theexpandedY parts to normal load position. it' therebound movei'nent is ot ,large amplitude there will also be some leakage of yfluid from the 'upper'compartment of the air spring chamber into the lowerV vacuum compartmenttive' stress, on 'the expanded parts. The po-` tential forces tending to return the members 'from the rebound positions R-r to the normal load position N-n'arevtherefore of less magnitude than those developed during-the displacement movement itself; and the recoil of the elastically strained suspension units is Aretarded or slowed. down to a degree that can be partially controlled by the tightness ot the joints between the members 9l-llban'd 36-87- Fig. l2 depicts a third suspension system-here shown as applied to aV rearaxle asseniblage-ivliich further exemplifies my genericr improvements. In this organiza tion twolever supports are used to operatively connect the main and the supplemental spring units ot the system. One-of these lever elements-here indicated by the ret'- erence character 5C-is pivotally mounted, at

6C, on an axle bracket 8c; and is coupled at the sides ot the link C and 'engages withA Jfriction rollers 56, 56, that are rotatably mounted thereon. -The rearwardly `extending uportion of this lever may be madein 'the form of a transversely rigid bar (e. g., like that illustrated in Fig. 4) but, as here shown, it consists of a flexible leaf spring 57 that is coupled at its eye end to the swinging frame 54. The plunger 9c is reciprocably mounted in a casing llc which is attached to the body horn 2 bymeans of theV bracket support 33C and the bolts- 1.20-340 etc. The movement of the plunger` in the casing is resisted by two counteracting spring elements which may be of the same general form and `character as `those illustrate/d in either Figs.

l and 2, or Figs. 8 and 9.

The mode of operation of the system last considered is generically the saine as that the main spring l is transmitted in series to vthe compression-resisting-supplementalispring element through the lever-link and plunger noinbcrs C 55-56-30-$). )When the, load is kinetica-llyincreased the ioo approach of the-body and axle members `is l resisted by the concurrently increased Yand superimposed lexures of these series-connected springs, Aand also by a slightly' increased bending kof the leverspring arm 5! "When the system is subjected to a rebound or expansion shock the lever 5C is rocked in la clockwise direction on its axle support-Gc (by the action of the one-way connectionsl 13e-43) and the magnied movement o'j its outer end is communicated, inparallel,

i* vto VKthe rebound checlc auxiliary spring Amental-'auxiliary suspension' unit ofthe conibination shown in Figs. 1 and 2; but which is'here illustrated as a part of the organization shown in Fig. 12; In thisconstruction they lower portion of the vcup shaped plunger 9G is Vlaterally supported and guidedby a i 40, 110, 42C and 439 that'are clampedv thereon removable bushing 597th'at screws into the bottom oi' the casing 11C; and the upper end rof the said plunger is provided with a series of'cup washers and spacing'ringsv 506., V60,

by the annular collar 36C.' Each one of the flared washersY 502140, and 422 is vso shaped andheld'asjto make ,close sliding engage- -ment with the inner 4wallof the casing 11C; 'and `the freeedgeof the upperwasher 472.- yis pressedvtightly against its bearingsurface by the beveledexpander ring 44C and the co'ilspring 61. The spacing ring dl is provided onvone side with a port 48, 'which'is inregistry with ay corresponding opening -in the wall of the plunger 9C;V and the inner Y end V'of this openingis covered by'a check valve 47C.' YThe upper extremity ofthe col- Y lai' 36 has in inwardly turned flange which Vis adapted to engage the head of an inner plunger or sleeve 37C thatis slidably mounted on Vaihollow cylinder 39C; andthe latter is, in turn, engaged by thel piston head of a follower bolt 18c thatis' secured to the cap of the casing 411 by the nut 62. `A

lpowerful coil spring 21c is interposed be,`

tween the flanged head of the s leevejc and the cap 63 on thelowe'r end ofthecylinder 39; :and the latterxis4 preferably spaced a slight distanceV above the adjacent closed end 'of the plungerQ` when the latter isin'its normal load position; l|l'Che bracket 33C car ries a cap which contains an inwardly open` ing valve 51?; and passageV waysl 52C lead from .the inner side Aof this valve, through the bracket 33C' and the wall of the casing 11, to the lower end of the lannular chamber 53 between theparts, 9-11-5Oc and 59.v

" "lhe enclosed chamber between the cup i l'shaped plunger l9 and the casing llcV is lpartiallyy iilled withfviscous,v oil to a level fsomewhat Aabove the contact jointfbetween the partsB-SQC (eig, to the level'Ln) and thev lower part of the'fhollow cylinder-39Vc 'is also preferably lilled 'with grease 'or parallin. The Aupper part-20c of theclosed chamber is then charged with afcompressed air (through a suitable valve 29y that is carried in the upperend of theboltglS) at 'Such pressure-aswill su'liice to maintain the parts in the vpositions shown in Figs. 12 and 13 when the.l suspension system is subJected to normal load. Then the load stressis increased the casing 11c moves downwardly vwith respect Vto fthe Vplunger' 9erV (or vice versa) ,and this movement breaks the contactbetween the members 560-37 (as shown in? the dotted lines oi'Fig. 14) thus estabfA lishing an openvcommunication between the upper and lower compartments of the air spring. and casing members brings the plunger 99 The initial approach oi' the plunger into engagementy withk thelower capr63 ot' Y the cylinder' 39C, and thus moves thej latter upwardly with respect to the head of the coincideiitlyy compressed by thel continued relative approach oflthe parts; and the freysultanty progressive 'increase in the ,pneumatic resistance to suchzV approacli--move 'ments acts,in series with 'the concurrent `in creased iiexure ofthe main spring .1,to ab l lsorbfaiid restrainythe-eliects ofcompressive shocl'rs.- vrDuring this phase of the operation vthe annular chamber 53C, between` the end proach, Ior compression displacement, is

The air whichv is conlin'edl in the jconjipaitnient 20?, and the airwhich is in n vthe upper iend ofthe cylinder 390{is thus of vthe ,bushingv 59 and the packingwasher '59s, is enlarged,and is kept filled with air p Vat atmospheric `pressure .through the rin- Y Iwardly openingzvalve '5110. kVVhenrthe afp-7160 checked and thepartsV begin to return to- Y ward normal load position, the valve 51c closes andtheairwhicliis trapped in the chamber cris compressed by this reverse movement; and a pneumatic check, or damp# ing action, is thus imposed on the free recoil of the air spring elements.l r

t-io`n,is.'subjectA to'rebound, or to an expansion stress, the yplungerassembly, 9-360,

tothe casings'upports 11C-#83, etc., (in the manner previously described) and this movement produces a further compression oi 'the trappedv air in the'now contracting chainber bet-weeirthe parts 50c-59. This sep- `a'i'ation of the parts-Quand ll'also results v .3W-hen thesystem, now under considerain the relative approachxof the innerV plunger 3f (which 1s carried downward 'with 'the interengaged parts .9C-436e) and Ithe lower head, of the cylinder 39C' (which vvis car- Y spring. 219.-' The withdrawal-' of the cylinder 4ried upwardwiththe connected members v llc-'18")-a`nd produces a correspondingly mcreasedf compression ofthe reboundcheck 39C froin'theflower",cornpartmentof the air `spring chamber (below the sealed-'f engage'- 'nient-of thecalla-*136.c and-the sleevefcf) also v produces ab progressively' increased'` vacu- -um7 therein-' with an vaccompanyfing Vfall of etc., will be drawn downwardly, with respect Y vGO Ysuspension system; and these conjointly acting supplemental spring restraints all act in parallel,` i. e., in multiple relation, with the increased flexure of the main spring 1, in thus absorbing and abating the objectionable effects of rebound or expansion stresses.

' The above 'described drop in pressure, and 'in the oil level, in the lower chamber, permits the valve 17C to open, and permit any liquid which has leaked past the packing ring V12 to flow back into this lower chamber; and when the joint between the parts 36e-7 is again broken-on the initiation of' another compression movement-#the oil in both lower andvupper chambers once more becomes a single continuous mass, rEhe air Vwhich is compressed in the outer annular chamber 530, is prevented from passing into the recess between the oil packing rings 40C-212C'by the reversely turned washer 50c and the tightly fitting piston ring but a portion of this compressed air willfbe forced out through the sliding joint between the plunger 9c and the bushing 59 and will thus serve to keep this bearing free from dust and mud. y

Figs. 15 and 16 illustrate a second double-levelr-series-parallel-spring combination, which presents the same generic features of operation that characterize the preceding embodiments of my invention, but which differs from theV other illustrative exemplifications thereof in being so designed that the supplemental suspension units act' as a one way spring, which is always compressed in the same direction from normal load position. In this form of construction the outer end of the main spring l is pivotally connected to the adjacent extremity of a rigid lever 5d (by means of the cross bolt Lll) and the intermediate portion of this leveris coupled to the axle block 8? by the swinging shackle llinks 6d. The Outer end of th-e lever 5d is made in the form of a slightly concaved rocker block that is normally engaged with the curved rocker end 55d o'fa second lever 5M; and this part of Vthe second lever is pivotally attached to th'e'lower end of the supplemental spring plungerd, which is reciprocably mounted `in a casing- 11d and an extension bushing 59d bolted thereto. lThe casing 11d is rigidly secured to thebody horn 2 by means of Vthe bracket 33d and the bolts 12?, 34d, etc.;

and the intermediate portion of the leverk tenesse in series with the supplemental spring-byY the elements 4d-55d9d, etc.*and the parts are so adjusted that the one way connections 13d and 65 are both under slight tension. When the system `is `subjected to Vkinetic compression stresses the outer engaged ends of the two levers 5d, dfirmove as aunit toward the body casing 11d; and

the initial flexures oi the series-connected main and supplemental springs are `both progressively increased as this movement continues. 1n this phase of the operation the various spring and lever elements move from the full line positions N-n of Fig. 15 toward the dotted line positions C-c-c of Fig. 16 the ultimate position assumed by the lever dd being the saine as Vthat shown in full lines-in this figure. But when the body and axle parts are separatedbeyond normal load position-under 'theef- 'i fectof a rebound or expansion stress-the links 13d rock the lever 5d in a counterclockwise direction on its axle support,

'6d-8d; and the magnified movement of the outer extremity of this lever flattens o'r straightens out the main spring 1; while the pull of the tensioned strap 65 rocks the lever 5dd in the opposite, or-clockwise direction onthe body support MCL-33d, and thus simultaneously increases the initial compression of the supplemental spring in its casing support 11d. But in this phase of action the main and supplemental springs do not cooperate in series, but are coincidently liexed in vmultiple relationship; and the elastic restraint imposed on rebound movements is correspondingly greater than that imposed on equal (linear) movements of compression. 1n this case the ratio between the increased flexures of' the main and supplemental springs-when .they thus act in parallel-may be varied by shifting the position of the bolt connection 66 (between the strap 65 and the lever dd) g spect the suspension organization of Figs. 15 and 16 presents one detail feature of adjustment that is not present in the organizations of Figs. 1, 2,4, or12.

. Aspreviously stated any suitable form of one way spring may be used as the` supplemental suspension elementof the last considered organization. TheV form which I and in this re- A More specifically described the construction valve 71; and with a row of radial ports.

(whichy I' have designated as a semi-pneu matic s}1 1iiig,)y-wliich .act in parallelY to,`

elastically resist and check any movement ofthe plunger and casing parts 91-11d toward each. other; and of auxiliary pneuinatic damping means which retard and :est-rain the recoil or expansion movements ot the said parts Atoward normal load position.

consists" ot the -body suppoi'ted casing 11,

and the extension bushing 59d 'which is fitted Y closely into the lower end or' the casing and is secured thereto by the boltsV 68; thecup shaped plunger 9d, whicli'is provided at its upper edge with the cup washers and spac-r ing rings 502130, 40d, 412142Lv that vare clamped in place thereon ,by the flanged sleeve 36d; an'iniier plunger 39d, which is closely fitted to vthe .interior periphery ot the outer kplunger 9d and "is .held yin iiXed longitudinal relationshipto the casing 11d by the kbolt 18d; anda powerful coil-cour` pression spring 21d Whicliis interposed byetween'the inner and outer plungers, 89` and 9d. series of axial ports 7 0-7 0 which are closed at the top by the upwardly opening cheek 7:27 which are so positioned that when the parts are in normal loadposition (Figs. 15

and 17) these yports open into the annular vis closed at its Ilower end by an inwardly opening flap valve 47d. The annular space FiF-#between thel cup washer 50d the bush' ing;l 59S1 the plunger 9d andthe casing 11dis in` communication with the outside `air throughl the inwardly opening valve 51d and the passageway 52d; and the plunger 9d is'also provided with a short groove Y74:

that is normally in registry with a longi-L tudinal passage way on the inner bearing face ot the bushing' 59d.

In the use of this semi-pneumatic supplemental spring the interior chamber is preferablv filled with oil or grease to about vthe level L .(Figf17), and compressed airis then introducedythrough the valve 29d. until the'pressure in the upper space 20d is sufficient to balance the difference between the normal component of load stress on the body parts 2-111-.181-39d and the initiall tension of the coil spring 21d. and to' thereby maintain the relatively reciprocable members 9 and 11d' in static equilibrium when they are in the .expanded position of Figs.

. 1.5 and 17. In this position the ports -72 The member 39d is provided withy a.

The ring 41d is also` y are open vand the loil `below the piston 39a istlieretore subjected to they tullfpressure of the fluid above .that level. fWhen the System is subjected to either Va compressive or` an expansive stress-ifi.c ywhen vthe body and axle. parts move in .either direction from normal load position-'the plungei'f9. isp

`moved upwardlyT withresiect. tothe casing 11.(as .shown in Figs. 16and 18) and the "initial compressions ofv both the confined fluid and of the c'o-il spring 211 are simultaneously increased. f this compression movement-closes theports i2, and thus vshuts lott" communication between the upper and lower compartments of `fluid pressure chamber; but as the movey pressure by th'eropening r The initial phase'of rested either bythe series or parallel com- I l the suspension elements to normal load' posi- 95 tion--whicli involvesv the movement of'A the plunger f9`d away lfrom the paitsvlld-lS-wy 39d-isrestrained and retarded by the closing of the valve 71 and the formation ot a gradually increasing vacuumV (or af progres'sively decreased pressure) in "the eX` pandingspace below the piston 39d. This suction damping action is supplemented by the closingof the valve 51d and the proagressive compression ofthe'air trapped inf`105 the annular spacej'.v These twoc'oopera tive check actions on the recoil movements` progressively increase in magnitude asthe parts approach normal load position; but

when that position is "reached,v ,or nearly 110., reached, .both restraint-sare removed'g--the one by thefopening of the ports 72 'and-the reestablishment of free communication be-. tween the lower and upper compartments of' the air spring chamber. 'and the other by the 115 registry of the port 74 with'the groove 75 Aand the consequent discharge of the comwhich is above the' piston 39d'is prevented from returning to the lower compartment ot the air spring, and the'levelof the liquid therein will drop below that in the' groove Thisdrop in level-and the accompanying decrease in pressure in theflower chamber-+' will permit anyfluid which may have leaked past the. ring 42d, toy pass back, throughthe the ports 72 are again opened, the Valve 47d is immediately closed by the relling of the 'lower compartment With oil and the immediate reestablishn'ient of the normal air spring pressure therein. But any pumping of outside air into the groove in the ring ald-and thence into the loWer compartmentof the air spring-Will be prevented, as before, by the action of the packing rings 501-60d which cut off any inward flow of Huid from the outer ychamber 53d.

It Will now be obvious, to those skilled in rthis art, that all of the complete suspension organizations hereinbefore described present the same general combination of parts ;-viZ, a mainspring rigidly secured to the axle oil' the vehicle, a supplemental spring mounted on the body of the vehicle, and an intervening system of connections .conjoining contiguous ends of the said springs with the said axle and body parts in such manner that the elastic elements act in series When subjected to yan increase in loadr stress, and act in parallel or in multiple When subjected to rebound or expansion stresses-this action producing in each case an augmented elastic resistance of both springs to the accom-v panying displacements from normal load position. It Will further be apparent that all of the supplemental spring units herein shown or described as part of the aforesaid organizations are of the dual resistance type-i. e., they all present a progressively' increasing elastic resistance to any displacement or departure of the body and axle members from the position of static equilibrium-that resistance being afforded either by a single double-acting spring (as shown in Figs. 4t6 and `1748) or by a pair ofreversed or countenacting springs (as in Figs. l-Q, 8 9 and 12E-let).

It Will also be clear that the several forms of pneumatic or semi-pneumatic auxiliary springs, Which areillustrated in Figs. 8 to 1l, 1344 and 17-18, as constituting part of my entire invention, have certain general characteristics of structure and operation e. g., they all present a combination of pneumatic and metal-coil springs that are adapted to restrain, either successively or coincildently. lany displace-ment of the parts from normal load position;y they all include, as part of the combination, some means for pneumatically damping the recoilj ofA one or both of these springs after they have been subjected to an increased. or displacen'ient, strain :y they all have an internal piston or plunger which is adapted to divide the air spring chamber into two compartments that n are successively connected and disconnected vvith cach other as the relatively movable parts osclllate in opposite directions; they spring,

are all provided With means for permitting any fluid, which may leak from the air spring chamber', to be intermittently returned to one of the compartments thereof ufithoutthe use of any pump or other auxiliary mechanism such as is ordinarily employed for that purpose; and they are all further provided vvith supplen'iental guards for preventing any pumping or forcing of outside air into the interior of the air spring during the operation of the mechanism.

It has already been pointed out that the severalelements of the various suspension organizations hereinbefore described may be used alternatively or interchangeably in many generically analogous combinations; and, with the precedingdisclosure as a guide, those familiar with the design and use of such organizations, Will be enabled to utilize .my present improvementsin vvvhole or in part as may be desired-in numerous other shock absorber constructions, and in conjunction with other forms of main spring and chassis frame mountings that are not herein specically illustrated. do not, therefore, limit the scope of my invention by the particular examples Which Ihave given of its application. n y

l/Vhat I claim is: j

l. ln an elastic support system for relatively movable members the combination of a plurality of springs interposed therebetween, and means conjoining said members and said springs vhereby the latter are con-v nected in series when the members are forced toward each other, and are connected and increasingly flexed in parallel` When the members are separated beyond the position of static equilibrium.

2. In an elastic support system for vehicle bodies the combination of a Vmain leaf a supplen'iental spring, and connective means conjoining` said springs vvith the body and axle members of the vehicle, and

vacting` to progressively.increase .the superimpo=ed or series-induced .flexure of both springs when the system is subjected to compressive shocks, and also. acting` to coincidentlj.v increase the separate or parallel-ilu posed flevures of the same'springs when the system is subjected toA rebound or `expansion stresses. j y

ln an elastic support system for a vehicle chassis the combination of amain spring rigidly attached to one of the chassis members, a supplen'iental spring mounted on another relatively movable chassis i'uembel'` and a lever system interposed l'ietween the said members and the free ends of the said springs and acting` to successively couple the latter in series and'inparallel and to concurrently increase the tlexures thereof when the system is respectively subjected to coinpression and to expansion shocks.

Al. fin elastic support systein'for relatively les.

mielilisl 'i'riovable members which comprises the comel bination of a plurality ot springs interposed therebetween, means conjoining .said springs y in superimposed orseries relationship and imposing thereon a'progressively increased tiexfure when the said members are forced toward each other, and other means conjoin-y ing said springs vin parallel and subjecting them to coincidently augmented strains when the said members Aare separated beyond the position of static equilibrium. j

In an elastic support system for vehir-les the combination oitl a pluralityy otv springsr interposed between the relatively oscillating members of the vehiclechassis,l a

lever system conjoining said members with the Caid springs and `acting to' successively couple the latter'iii series and in multiple relationship when the chassis members are respectively displaced opposite directions'.

Jfrom normal load position, and means tor damping or retarding the recoil oit the said members from their displaced positions.l

6. In an elastic support system for vehicle bodies the combination of a main spring, a supplemental spring normally connected in series therewith and subjected to progressively increased tlexure whenv the main springis subjected to an increased load` vbers, a lever connected at one end with the contiguous extremities of the said springs, and pivotally mounted at another point on one of the said'movable members, and a flexible one way connection between a third point on the said lever andthe other oi said movable members whereby all ot said springs are subjected to increased tlexure when the members are moved from static load position.

'8. An elastic suspension systemxfor vehicles which comprises an air spring, means for dividing the fluid pressure chamber oit said spring into two compartments when' the said chamber is expanding, aseries oi packing rings tor ietardingleakage ot' fluid from the high pressure compartment, and means for intermittently returning any such said expansion. I

9. An elastic suspension unitr for vehicle bodies which con'ipriscs' two .mutually re'- ripr'ocable hollow members, arseries of paelc rexpansion stresses.v

j 18. Airelastic suspension system torve'- vhiele bodies which comprises the combinaleakage to the other compartment during' ing rings for retardi'ng leakage 'o'f fluid fromv the chamber enclosed by said members, an'

inner plunger'adapted to divide said cham:

ber into two compartments, means' for.' estaby lishingV -a 'ifi-ee v'communication between saidcompartments .when thev volumeoi' the enf-r closed'cha'mber is diminished bythe relative j f approach or the, i'eciprocable members and for-closing-said Acommunication when the Avolume 'ot' 'said'chamber'is increased by the 'reverseniovement of said members, and a valve controlled passageway leading from a point between said packing said compartments. c

10. An elastic vsuspension unit for two relatively movable `members which comprises a pair 'of hollow cup shaped bodies that are respectively attached to the rela-L tively movable 'members an inner plunger that is secured to one ofsaid bodies and is slidably` engaged with the otheryot them, a coil spring interposed between said inner plunger and thev relatively movablev body,

`and vmeans for `intermittently opening and closing communication' between the chamrings totone of Y lsok bers on theftwo sides of the innerfplunger Y f as ,the movable. members oscillate, about theirl normal or median position. 'l

11. An elastic suspension. system for vehicles which comprises in combination a inain'spring, a supplemental air spring normally coupled in series `therewith and subjected to progressively yincreased compression when the main spring is subjected to increased 'load stress, an auxiliary -coil spring, and means conjoining said springs f with the body and axle membersofy the vehicle land acting to impose simultaneously increased flexures on the said main spring vand the saidl coil spring when the system is subjected to rebound or expansion stresses.

l2. .A n elastic suspension system for vehicle bodies which comprises` the combina tion of a main'lea-f spring,y a supplemental im fluid pressure spring, mea-ns eonjoining said springs in series relationshipr andactin'gfto impose progressively increased strains there-V von when the vehicle body is forced toward the' axle 'member by an laugmented; load stress, a coil spring, and meansfor connect ing said coil spring in vparallel withsaid main spring and subjecting these springs to simultaneously increased l'exures when Ithe system is called upon to resist rebound' or tion of a main spring. a supplemental 'fluid pressure spring normally connected in series with said main spring. a coilspring 1noiint-l ed in parallel relationship to said Huid pressure spring, means connecting said coil spring in parallel with said main spring when the system is subjected to expansion "stress, and means 'for damping the recoil ol the system when the suspension units haveA been displaced from normal load position.

Ill. In an elastic suspension system tor vehicles the combination o a main spring,

a supplen'iental air spring Cooperating in 1-95 meeting` said main and auxiliary springs in parallel with the body and axle members of the Vehicle and actingto coineidently i1n-,

pose increased flexural strains thereon when the said members are separated beyond normal load position, and means for pneumatieally damping the recoil or' the system after it has been subjected to compression or expansion stresses. i

In testimony whereof I have hereunto set my hand.

FRANK L. o. WADsWoRTH. 

